• 2 months ago
Understanding Diodes: Internal Composition and How They Work in a Circuit...
Like❣️ comments Share
.
#diode #diodes #diodeworking #diode3danimation
#3danimation #3delectronics #3delectrical #diyelectronic #diyelectronics #diyelectronica #diyelectronicsprojects #diyelectronicproject #diyelectronicguru #electronic #electronics #electronica #electronicwork #electronicworks #electronicstudent #electronicstudents

Category

📚
Learning
Transcript
00:00In this video, we'll explain what diodes are, their internal composition, and how they function in a circuit.
00:07A diode is essentially an electronic check valve for current.
00:10It allows current to flow in one direction, but blocks it in the opposite direction.
00:15Diodes typically have a marking on one end, which indicates the cathode, while the unmarked end is the anode.
00:22When the cathode is connected to the negative terminal of a power supply,
00:26and the anode is connected to the positive terminal,
00:29the diode behaves like a closed switch, allowing current to pass through.
00:33However, when the polarity is reversed, the diode acts as an open switch and blocks the flow of current.
00:40This unique property is due to the semiconductor materials that make up a diode.
00:44The most common semiconductor used is silicon.
00:47Let's consider a silicon atom, which has four valence electrons in its outermost orbit.
00:52These valence electrons bond with neighboring silicon atoms through covalent bonding
00:57to form the crystalline structure of silicon.
01:00In its pure state, there are no free electrons available to conduct electricity,
01:05so silicon behaves like an insulator.
01:08However, when external energy in the form of voltage is applied,
01:12some electrons break free from the covalent bonds,
01:15becoming free electrons that can move through the crystal and conduct electricity.
01:20This transformation makes silicon a semiconductor, transitioning from an insulator to a conductor.
01:26Pure silicon, however, is not sufficiently conductive for use in diodes.
01:30To enhance its conductivity, a process called doping is employed.
01:35Doping involves introducing atoms of another element into the silicon crystal.
01:39For example, when a phosphorus atom, which has five valence electrons, replaces a silicon atom,
01:46four of its valence electrons bond with neighboring silicon atoms,
01:50while the fifth electron remains free to move through the crystal, enabling electrical conduction.
01:55Since electrons are the mobile charges in this scenario, this process is known as n-type doping.
02:02On the other hand, p-type doping involves introducing a boron atom, which has only three valence electrons.
02:08A boron atom needs an extra electron to complete its bonds with neighboring silicon atoms,
02:14leaving behind a vacancy called a hole, which behaves like a positively charged particle.
02:19As the hole moves by, attracting electrons from neighboring atoms,
02:23it creates new holes, which is referred to as hole movement.
02:27Since holes are the mobile charges in p-type doping, it is called p-type doping.
02:32In a diode, one side of the semiconductor is doped as p-type, and the other side is doped as n-type.
02:40These are known as the p-region and n-region of the diode.
02:44At the junction between these two regions, electrons from the n-region and holes from the p-region
02:49are attracted to each other, trying to cross the junction.
02:53Once a sufficient number of charges cross, they create a depletion region that prevents further charge flow.
02:59When the p-region is connected to a positive potential, and the n-region to a negative potential,
03:04the electrons and holes are pushed toward the center of the diode.
03:08However, the depletion region blocks them from moving further.
03:12The electrons and holes in the depletion region are held together by a certain force.
03:17Once a voltage greater than 0.7 volts is applied, these forces are overcome,
03:22and the charges are free to move.
03:25This allows current to flow through the diode.
03:27This process is called forward biasing.
03:30In contrast, when the p-region is connected to a negative potential, and the n-region to a positive potential,
03:37the electrons and holes are attracted towards the terminals and accumulate there.
03:41This widens the depletion region, blocking the flow of current through the diode.
03:45This condition is known as reverse biasing.
03:48And that's how a diode works.
03:50I hope you learned something from this video.
03:52Don't forget to subscribe and turn on notifications to see future uploads.

Recommended